From f89df3f381f1e1247ddccdf178f203c06fddf5ce Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Wed, 6 Jan 2016 20:11:25 +0100 Subject: [PATCH] mdio_bus: Add comment to mdiobus_scan() and __mdiobus_register() Make it clear that mdiobus_scan () will only find devices which have a vendor/product ID in registers 2 and 3. These are typically PHY devices. Other sort of MDIO devices, such as switches, are not expected to be found during the scan. Similarly, __mdiobus_register(), which calls mdiobus_scan() will only find PHY devices, and other sorts of MDIO devices are expected to be instantiated from device tree. Signed-off-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/mdio_bus.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 0d369ad19d17..6f9ca51446db 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -291,7 +291,9 @@ static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio, * Description: Called by a bus driver to bring up all the PHYs * on a given bus, and attach them to the bus. Drivers should use * mdiobus_register() rather than __mdiobus_register() unless they - * need to pass a specific owner module. + * need to pass a specific owner module. MDIO devices which are not + * PHYs will not be brought up by this function. They are expected to + * to be explicitly listed in DT and instantiated by of_mdiobus_register(). * * Returns 0 on success or < 0 on error. */ @@ -394,6 +396,18 @@ void mdiobus_free(struct mii_bus *bus) } EXPORT_SYMBOL(mdiobus_free); +/** + * mdiobus_scan - scan a bus for MDIO devices. + * @bus: mii_bus to scan + * @addr: address on bus to scan + * + * This function scans the MDIO bus, looking for devices which can be + * identified using a vendor/product ID in registers 2 and 3. Not all + * MDIO devices have such registers, but PHY devices typically + * do. Hence this function assumes anything found is a PHY, or can be + * treated as a PHY. Other MDIO devices, such as switches, will + * probably not be found during the scan. + */ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr) { struct phy_device *phydev; -- 2.20.1